1. Field
This disclosure relates to sources for millimeter wave (MMW) RF power, and to high power sources for W-band applications in particular.
2. Description of the Related Art
Sources of medium and high power MMW radiation can be applied in communications systems and in directed energy weapons. While lower frequency MMW wave applications can now be satisfied with solid-state sources, high power sources for the W-band (75 GHz to 110 GHz) and above traditionally incorporate tubes such as magnetrons or gyrotrons. However, such tubes are expensive, bulky, fragile, and require high voltage electrical power. Thus MMW sources incorporating tubes are not readily portable.
Semiconductor devices are now available for use as oscillators or amplifiers in the W-band, but the available power output from each semiconductor device may be limited to no more than a few watts. Thus medium and high power solid state W-band sources may use quasi-optical methods that combine the power output from a large plurality of semiconductor devices within a waveguide or in free space. Approaches that have been suggested for combining the power output from plural semiconductor devices include the reflect array amplifier described in U.S. Pat. No. 6,765,535, the grid array amplifier described in U.S. Pat. No. 6,559,724, and the lens array or tray amplifier described in U.S. Pat. No. 5,736,908.
Throughout this description, elements appearing in figures are assigned three-digit reference designators, where the most significant digit is the figure number and the two least significant digits are specific to the element. An element that is not described in conjunction with a figure may be presumed to have the same characteristics and function as a previously-described element having a reference designator with the same least significant digits.